color

color: red;
color: #ff0000;
color: #f00;
color: rgb(255, 0, 0);
color: rgba(255, 0, 0, 0.5);
color: rgb(100%, 0%, 0%);
color: hsl(0, 100%, 50%);
color: hsla(0, 100%, 50%, 50%);